After listening to the tape, I must say that the controller was very calm and composed; like it happened to her every day of the week (maybe it does...).
Last month I was flying through Dallas and a Seminole went nordo for about 10 minutes. When they finally answered (3 miles from their destination of Arlington and still at 6000') the controller went postal on him for overflying DFW without responding.
If I was her I would have chewed them out bigtime!